Lock-top envelope



May 15, 1956 w. H. KELLY LOCK-TOP ENVELOPE Filed May 21 Fig. 2

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United States Patent ti LOCK-TOP ENVELOPE William H. Kelly, Cohoes, .N. Y assignor to Cohoes Carry'bag Company, Inc., a corporation of New York Application May 21, I954, 'Seria'l Dim-431,564

3 Claims. ((1229-77) This invention .relates to envelopes and ,more particularly ,to means for releasably securing .the cover flap to the bo y of the envelope to retain articles ,placed therein.

The need has .long existed in the container art for a means forquickly and securely closing envelopes and the like without the aid of snaps, metal fasteners, buckles, tapes, strings, etc. and which permits the ready access to the interior thereof when desired.

The primary object of .this invention .is to provide a closure means for envelopes and the like which accomplishes the desirable functions stated above.

Another object .of my invention is to provide locking means which may be incorporated in envelopes without introducing additional steps in the envelope rconstrucn'on.

Still anotherobject of this invention is .to provide fastening means for envelopes which may be economically produced .and which eliminate the scrapping problems present in the manufacture of other -forms of closure means in use today.

In the accomplishment of these and other objects, I

provide as one important feature of this invention a pair of arcuate slits in the front and back panels of the envelope which receive a tongue formed in the cover flap to retain the flap in its closed position.

An envelope constructed in accordance with this invention has many advantages, one of the most important of which is its ease of operation. By a single motion of the thumb or finger, the flap may be moved to its closed position and the tongue forming part of the flap may be inserted through the arcuate slits to its locking position. A pair of ears on the side of the tongue perform the look ing function. To release the flap it is only necessary to press the tongue through the slits from the other side of the envelope. An envelope of this type may be opened and closed repeatedly without decreasing the efliciency of operation of the locking means.

These and other objects, features, and advantages of my invention will be more readily understood and appreciated from a detailed description of one embodiment thereof selected for purposes of illustration and shown in the accompanying drawing, in which:

Fig. 1 is a rear elevation view of an envelope embodying this invention with its flap in open position,

Fig. 2 is a front elevation view of the envelope illustrated in Fig. 1,

Fig. 3 is a fragmentaryview in rear elevation of the envelope with the flap in its locked position.

Fig. 4 is a fragmentary view in front elevation of the envelope with its flap in the position illustrated in Fig. 3,

Fig. 5 is an enlarged fragmentary view of the locking means in its closed position, and

Fig. 6 is a view in section taken along corresponding section lines 66 in Fig. 5.

Proceeding now to a detailed description of this invention, the envelope illustrated in Fig. 1 comprises a rear panel 10, a front panel 12, and a flap 14. These elements may be formed as a single integral blank or stamped as separate units. The specific means employed forms no 2,745,595 Patented May '15, 1956 2 part of this invention. An arcuate slit 18 is cut in the rearpanel ofthet envelope adjacent'its upper rnarginal-edge and -,a similar :slit 20 coextensive ;therewith is cut in the front ,panel 12. The curved slits 18 and 20 face the upper margin of their respective panels for reasons that will becomeapparent presently.

The flap 14 which may be .of any desired shape 'has formed therein thy means of a substantially Mshaped slit 21, a tongue 22 'havingapair of ears'24. Itis to be noted that the slits 18, 20, and 21 are .formed by sing'le cuts in the rear panel, front panel and flap respectively. 'By this means, scrappinghas been entirelyeliminated. Although Fig. 5 shows the slits 18 and 121 as having a finite width, this has been done merely to aid in the presentation of the description and is not intended to be a true illustration of the ,preferred embodiment of this invention.

The manner :in which the flap :is locked in its closed position will now :be described in detail. A scored line lustrated-by 'the dotted line 26 is provided to facilit'ate the folding of the vflap to its closed position. Referring specifically to Fig. 1, ,the flap 14 will be folded along the line 26 to a position overlying the rear panel 10. When the flap is moved to its closed position, the body of the tongue 22 with the exceptionof its cars 24 lies within the area defined by the arcuate slit 18. By applying a force against the face of the tongue, its tears pass through the ends'ofthe slits -1-8 and :as "is-evidenced by an inspection of :Fig. 4. It is apparent that the :ease of operation permits the flap to be closed and locked in one extremely simple manipulation.

The enlarged viewzof Fig. 5 best illustrates the position of the-tongue in its locked position. Viewing the envelope from the rear, the ears '24 are observed to have passed through :the ends of the slit 1 8 and also through the similar portion of the slit 20 and rest against the front panel 12.

To release the flap from its locked position it is only necessary to apply a force against the front panel 12 within this area defined by the slit 20. In this manner the ears are pressed through the slits 20 and 18 free of the margined portions thereof. The flap 14 is then free to pivot about the scored line 26 to its open position and access to the interior of the envelope is available.

The envelope just described with its new locking means accomplishes all of the objects and provides all of the advantages set forth in the introductory paragraphs of this specification.

Bag machines employed in the manufacture of envelopes may, by the addition of dies to cut the slits 18, 20, and 21, produce envelopes incorporating this invention without suffering a reduction of output per unit of time.

The lock means described may be used on countless types of envelopes which do not require a handle. For example, they may be employed as containers in 4th class mail carrying such items as catalogues, fiyers, brochures, etc. or they may find suitable use as photograph bags.

If the envelope employing the described locking means is to receive extended and repeated use, or if the weight of the material to be carried by the envelope is excessive, it may prove desirable to incorporate stiffeners into the bag about the slits 18, 20, and 21 to increase the life of the locking means. The stifieners may take the form of heavy paper or. cardboard. A pair of such stifieners 16 and 23 are illustrated in Fig. l. The stiffener 16 comprises a single thickness of material which overlies the slit 21, scored line 26, and the slit 20 and is provided with similar slits and a scored line to permit the locking of the flap in the manner described. The stifieners may be secured by any adhesive coating on its surface in contact with the inner surface of the flap and front panel of the envelope. The second stifiening number 28 is secured to the inner surface of the rear panel of the envelope and contains a slit coextensive with the slit 18. The function performed by the stifieners is obvious, namely, to retain the shape of the envelope and resist tearing of the slits 18, 20, 21, and the ears 24. V

Obviously, if it is deemed desirable to employ reinforcing members for the locking means, separate stifieners may be used for the tongue 22 and the slit 20 instead of the single member 16 illustrated.

Having described one embodiment of the invention, other forms of thisinvention will readily occur to those skilled in the art to which it pertains. Therefore, it is not my intention to be limited to the specifically described and illustrated embodiment but to the appended claims and their equivalents.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An envelope comprising a front panel, a rear panel, an opening between adjacent edges on one side of the panels providing access to the interior of the envelope, a cover flap connected to, the edge of the front panel adjacent the opening and folded down over the rear panel to close theopening, a stitfening member secured to the inner surface of the rear panel adjacent the opening, a

second stiflening member secured to the inner surface of the cover flap and extending over the inner surface of the front panel adjacent the opening, coextensive slits cut in the front and rear panels and through the stifliening members and underlying the cover flap, said slits being concave as viewed from the opening, and a slit cut through the cover flap and the second stifiening member forming a tongue having a pair of ears which extend down and to the sides of the central portion of the tongue and overlie the sides of the concave slits in the front and rear panels while the central portion of the tongue terminates short of the central portion of the concave slits, the ears of the tongue being inserted through the sides of the slits in each of the panels to lock the cover flap in the closed position.

2. An envelope comprising a front panel, a rear panel integrally formed with the front panel, an opening between adjacent edges ofthe panels, a foldable cover flap integral with one of the panels and covering the opening, coextensive arcuate slits facing the opening cut in the front and rear panels and underlying the cover flap when it is folded to close the opening, and a slit cut in the cover flap and forming a tongue having ears on its sides which overlie the terminal portions of the arcuate slits, the central portion of the tongue terminating short of the central portions of the arcuate slits, said ears being inserted through the terminal portions of the arcuate slits to lock the cover flap over the opening.

3. An envelope comprising a front panel, a rear panel integrally formed with the front panel, an opening between adjacent edges of the front and rear panels, a foldable cover flap integral with and extending upwardly from the edge of the front panel adjacent the opening, a stiffening member secured to and covering the central portion of the inner surface of the cover flap, arcuate slits cut through the upper portions of the front and rear panels and facing the opening, and an M-shaped slit cut in the cover flap and the stiffening member and forming an upwardly extending tongue having enlarged ears which extend upwardly and to the sides of the body of the tongue when the flap is in the open position, the ears of the tongue overlying the terminal portions of the arcuate slits when the cover flap is folded down over the opening against the outer surface of the rear panel, said ears being inserted through the arcuate slits and overlying the outer surface of the front panel to lock the cover fiap in the closed position.

References Cited the file of this patent UNITED STATES PATENTS Potdevin Nov. 14, 1922 Lackey Dec. 31, 1929 611,788 Great Britain Nov. 3 1948 

